Natural selection on flower size in invasive Cytisus scoparius along an elevation gradient

Abstract

Aims Established invasive plant species have more diverse gene pools than single populations in their home range. This genetic and often phenotypic variation allows for natural selection to act and produce rapid adaptations as an invasive species interacts with other members of the community. For an invasive flowering plant, interactions with pollinators may lead to adaptations to a heterogeneous pollinator community. The variation in the pollinator community in the invaded range is similar to variation in the native range, suggesting that adaptations may mirror patterns seen in the home range. In this study, we investigated variation in flower size in Cytisus scoparius, an invasive leguminous shrub, along an elevation gradient. Methods This study took place in the Capitol State Forest in Washington State. We measured flower widths and the proportion of visited flowers, using 10 plants per field site. Sites were located along an elevation gradient and were visited three times to measure phenological variation on a per-plant basis. Important Findings We saw positive selection for flower size, albeit without a distinct pattern of higher selection at higher elevations. The pattern of natural selection could be seen both in terms of pollinator visitation rates and in seed production. We also found that the largest contributor to changes in seed production was not elevation or flower size but management practices.

Divergent Responses of Floral Traits of Lonicera nervosa to Altitudinal Gradients at the Eastern Margin of Hengduan Mountains

“…The local flower size adaptations of plants to elevational gradient may be affected by biotic factors, such as pollinator community (Kuriya et al, 2015) or simply by the abiotic selective pressure, regardless of changes in the pollinator community (Bode and Dufresne, 2020). Previous research has shown that some plant species tend to develop larger flowers at a higher altitude (Malo and Baonza, 2002;He et al, 2017;Bode and Dufresne, 2020), while some studies have shown that there is no common regularity in the correlation between floral size and altitude itself (Nagano et al, 2014). When both floral display size and flower color vary within a plant species, each has the potential to play an important role in pollinator attraction and subsequent seed set (Malerba and Nattero, 2011).…”

The dispersal-related traits of an invasive plant Galinsoga quadriradiata correlate with elevation during range expansion into mountain ranges

“…Trait variation among populations has been associated with changes in natural selection pressure along elevation ( Bode and Dufresne 2019 ). Long-term adaptation to environmental factors would thus result in genetically based changes in phenotypic traits ( Marin et al 2019 ; Pimpinelli et al 2019 ).…”